I had two ingot presses. I'd like to sell one, but I can't find a way to split the stack. This answer provides a work-around involving placing stacks in crafting screens, but that doesn't work for the crafting items. Placing my smelters in the smithing kit didn't separate them. Placing them in themselves didn't do it. Placing them in the Lutefisk Cube turned them both into lutefisk!

I'd like to avoid another lutefisk incident. How can I split stacks of crafting items?